Is it better to break one's fast with dates on the Day of Sacrifice for one who is accustomed to that throughout the year, or to forgo it on this day?

The Sunnah (definition) on the day of 'Eid al-Nahr (Eid al-Adha) is for the sacrificer to delay eating until he returns from the prayer. The eating should be from his sacrificial animal immediately upon his return from the prayer ground. This is explicitly stated in narrations, that one should refrain from eating before the Eid prayer, and some of them explicitly state eating from the sacrificial animal after the prayer.